Method and apparatus for rasterizing transparent page

ABSTRACT

A method for rasterizing a transparent page comprises interpreting the transparent page to obtain graphic entities, transparency properties of the graphic entities, and profile information of the graphic entities; dividing the transparent page into a transparent area and a nontransparent area according to the transparency properties of the graphic entities; identifying, from the graphic entities, an overlapping graphic entity having an overlapping portion with the transparent area according to the profile information of the graphic entities; and dividing the transparent area into a de-transparentizing area and an ultimate transparent area by using the overlapping graphic entity.

RELATED APPLICATIONS

This application claims the benefit of Chinese Patent Application No.201110460603.6, filed Dec. 31, 2011, the entire contents of which areincorporated herein by reference.

FIELD

The present disclosure relates to rasterization and, more particularly,to a method and apparatus for rasterizing a transparent page.

BACKGROUND

A raster image processor (RIP) is a unit for interpreting and convertinglayout information described in a page description language into datainformation that can be output by an output equipment. For example, anRIP may interpret and convert graphic entities in PDF (Portable DocumentFormat) format into data that can be output by the output equipment. RIPis a core software of the pre-printing industry, which may determine theoutput speed of a desktop system.

Two imaging models are usually used for drawing page graphic entities bythe RIP: substitute imaging model and transparent imaging model. In thesubstitute imaging model, a graphic entity newly drawn in a pagecompletely substitutes for a background content at a position of thegraphic entity, where the background content may be a graphic entitypreviously drawn in the page. The final colors of points at thisposition are determined by the graphic entity finally drawn at thisposition. In the transparent imaging model, a transparent graphic entitynewly drawn in a page is subjected to transparent computing with abackground content at the position of the graphic entity. That is, thefinal colors of points at this position are determined by all thegraphic entities drawn at the position.

A PDF format is an electronic document format for describing pagecontents. From version 1.4 of PDF, transparency concept and transparentimaging model are introduced. A PDF page can support various specialeffects such as transparency, gradient, feathering, and etc.

RIP can interpret and convert the layout information described in a PDFpage description language into 1-bit format data or 8-bit format datafor output. The 1-bit or 8-bit refers to a number of bits of a colorvalue of a color component of a pixel. For example, if four colors, suchas C, M, Y, and K, are used to represent the color of one pixel, whenRIP performs 1-bit data output, 4-bit data is required in total, i.e., ½byte; while when RIP performs 8-bit data output, 32-bit data is requiredin total, i.e., 4 bytes. If an output equipment requires 1-bit output,under the substitute imaging model, a graphic entity to be drawn isfirst screened to generate 1-bit data, and the 1-bit data is drawn to anultimately-output 1-bit page dot matrix. Under the transparent imagingmodel, if a graphic entity to be drawn is first screened, the resulting1-bit data cannot be subjected to transparent computing with backgroundcolors. Therefore, transparent graphic entities need to be assembled ina manner of 8-bit data output at first, then an 8-bit data dot matrix ofthe whole layout is screened according to one image-type graphic entityto obtain 1-bit data, and the 1-bit data is drawn to anultimately-output 1-bit page dot matrix. Therefore, the rasterizationspeed of the RIP is relatively low.

An early RIP rasterization method comprises determining, by scanning apage, whether transparent graphic entities are contained in the page. Ifthe page contains transparent graphic entities, it is determined to be atransparent page. Each pixel in the transparent page is subjected totransparent mixing operation with the background according to thetransparent model, obtaining an ultimate 8-bit page dot matrix. Sincenot all areas in the transparent page contain transparent graphicentities, such a method may need to handle a large amount of data,resulting in a low rasterization speed.

To improve the rasterization speed of a RIP, in a conventional method, atransparent page is divided into a transparent area containingtransparent graphic entities and a nontransparent area not containingtransparent graphic entities. The transparent area is assembledaccording to the transparent model and the nontransparent area isassembled according to the substitute model. The data amount oftransparent processing is reduced as compared to the situation in whichthe entire page is assembled according to the transparent model.However, in the conventional method, assembling the transparent graphicentities of the transparent area is based upon pixels under theequipment coordinate space, and the transparent graphic entities aresubjected to transparent computing with background during theassembling. Therefore, when the transparent computing is performed,graphic entity data and background data may already have the equipmentresolution. The equipment resolution may be as high as 2,400 dpi, oreven higher, thus the data amount of transparent computing may be large.In addition, formula for the transparent computing may also be complex.As a result, the transparent computing may still be time consuming.

SUMMARY

In accordance with the present disclosure, there is provided a methodfor rasterizing a transparent page. The method comprises interpretingthe transparent page to obtain graphic entities, transparency propertiesof the graphic entities, and profile information of the graphicentities; dividing the transparent page into a transparent area and anontransparent area according to the transparency properties of thegraphic entities; identifying, from the graphic entities, an overlappinggraphic entity having an overlapping portion with the transparent areaaccording to the profile information of the graphic entities; anddividing the transparent area into a de-transparentizing area and anultimate transparent area by using the overlapping graphic entity.

Also in accordance with the present disclosure, there is provided adevice for rasterizing a transparent page. The device comprises a pagedescription language interpreting unit and a de-transparentizing unit.The page description language interpreting unit is configured tointerpret the transparent page to obtain graphic entities, transparencyproperties of the graphic entities, and profile information of thegraphic entities; and divide the transparent page into a transparentarea and a nontransparent area according to the transparency propertiesof the graphic entities. The de-transparentizing unit is configured toidentify, from the graphic entities, an overlapping graphic entityhaving an overlapping portion with the transparent area according to theprofile information of the graphic entities; and divide the transparentarea into a de-transparentizing area and an ultimate transparent area byusing the graphic entities respectively having an overlapping portionwith the transparent area.

Features and advantages consistent with the disclosure will be set forthin part in the description which follows, and in part will be obviousfrom the description, or may be learned by practice of the disclosure.Such features and advantages will be realized and attained by means ofthe elements and combinations particularly pointed out in the appendedclaims.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory onlyand are not restrictive of the invention, as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is distribution diagram of the transparent area and thenontransparent area in the transparent page provided in an embodiment ofthe present disclosure;

FIG. 2 is an integrated flowchart of a method for rasterizingtransparent page provided in an embodiment of the present disclosure;

FIG. 3 is a flowchart of a method for rasterizing transparent pageprovided in an embodiment of the present disclosure;

FIG. 4 is a flowchart of de-transparentization processing fortransparent graphic entities provided in an embodiment of the presentdisclosure;

FIG. 5 is a flowchart of assembling content of a transparent pageprovided in an embodiment of the present disclosure;

FIG. 6 is a profile diagram of graphic entities in a transparent pageprovided in an embodiment of the present disclosure;

FIG. 7 is a distribution diagram of a transparent area in a transparentpage provided in a embodiment of the present disclosure;

FIG. 8 is a distribution diagram of cells generated by ade-transparentizing unit provided in an embodiment of the presentdisclosure;

FIG. 9 is a structure diagram of a device for rasterizing transparentpage provided in an embodiment of the present disclosure;

FIG. 10 is a structure diagram of an assembling unit provided in anembodiment of the present disclosure;

FIG. 11 is a structure diagram of a device for rasterizing transparentpage provided in an embodiment of the present disclosure.

DESCRIPTION OF THE EMBODIMENTS

Hereinafter, embodiments consistent with the disclosure will bedescribed with reference to drawings. Wherever possible, the samereference numbers will be used throughout the drawings to refer to thesame or like parts.

Consistent with embodiments of the present disclosure, a transparentpage refers to a page containing transparent graphic entities, where thetransparent graphic entities are graphic entities with transparencyproperty. In the transparent page, areas not containing transparentgraphic entities are nontransparent areas and areas containingtransparent graphic entities are transparent areas. Not all the areas inthe transparent page are transparent areas. FIG. 1 schematically shows adistribution of transparent areas and nontransparent areas in atransparent page. Graphic entities in the transparent areas areassembled according to a transparent model, and graphic entities in thenontransparent areas are assembled according to a substitute model.

Graphic entities forming the transparent areas may be of differenttypes, such as graph-type graphic entities, image-type graphic entities,and shading-type graphic entities. For example, some page contents maycomprise only one or more graph-type graphic entities, some pagecontents may comprise only one image-type graphic entity or oneshading-type graphic entity, and some page contents may comprise amixture of different types of graphic entities. The page contentscomprising only graph-type graphic entities, or the page contentscomprising only one image-type graphic entity or one shading-typegraphic entity, may have relatively less information, and can besubjected to de-transparentizing, i.e. transparent computing, before theassembling, to reduce the number of transparent areas, so as to reducethe data amount of the transparent computing and improve therasterization speed of the RIP.

Consistent with the present disclosure, a transparent page is firstdivided into transparent areas and nontransparent areas, and thetransparent areas are divided into de-transparentizing areas andultimate transparent areas. Before assembling the page contents, graphicentities in the de-transparentizing areas are subjected tode-transparentizing, i.e. transparent computing, so as to eliminate thetransparency property of those transparent graphic entities. The graphicentities in the nontransparent areas and the de-transparentizing areasare assembled according to the substitute model, while the graphicentities in the ultimate transparent areas are assembled according tothe transparent model. The assembled data in these three areas arecombined and output to equipment. As a result, the rasterization speedof the RIP may be improved.

FIG. 2 schematically shows a method for rasterizing a transparent pageconsistent with embodiments of the present disclosure. As shown in FIG.2, at S101, a transparent page is interpreted to obtain graphicentities, transparency properties of the graphic entities, and profileinformation of the graphic entities. At S102, the transparent page isdivided into a transparent area and a nontransparent area according tothe transparency properties of the graphic entities. At S103, graphicentities having an overlapping portion with the transparent area areidentified according to the profile information of the graphic entities,and the transparent area is divided into a de-transparentizing area andan ultimate transparent area by using the graphic entities having anoverlapped portion with the transparent area. At S104, the graphicentities in the de-transparentizing area, the graphic entities in theultimate transparent area, and the graphic entities in thenontransparent area are assembled.

FIG. 3 shows the details of the method for rasterizing transparent pageconsistent with embodiments of the present disclosure. At S201, pagecontents of a page are scanned to determine whether the page is atransparent page. The page may be determined to be a nontransparent pageif the page does not contain a transparent graphic entity. In thissituation, S200 is executed. The page may be determined to be atransparent page if the page contains transparent graphic entities. Inthis situation, S202 is executed.

At S200, the page contents are assembled according to the substitutemodel. After that, the process continues at S208.

At S202, the transparent page is interpreted and divided into atransparent area and a nontransparent area.

Specifically, the graphic entities in the transparent page areinterpreted and graphic entity information in the transparent page isrecorded in an intermediate file (intermediate instruction file). Thegraphic entity information may include a type of a graphic entity, atransparency property of a graphic entity, a location of a graphicentity, a profile of a graphic entity, and a color value of a graphicentity, etc. The type of a graphic entity may include graph-type,shading-type, image-type, and etc. The transparency property is used forindicating whether the graphic entity is a transparent graphic entity ora nontransparent graphic entity.

The transparent page is divided into a transparent area and anontransparent area according to the transparent properties of thegraphic entities in the page recorded in the intermediate file. That is,areas in the page covered by the transparent graphic entities arecounted in transparent area distribution information, and areas in thepage covered by the nontransparent graphic entities are counted innontransparent area distribution information. In some embodiments, anarea covered by a bounding rectangle of the graphic entity may betreated as the area covered by the graphic entity. The transparent areadistribution information and the nontransparent area distributioninformation are managed by a page resource distribution management unit.The page resource distribution management unit is further used formanaging de-transparentizing area distribution information and ultimatetransparent area distribution information to be written in the file asdescribed below.

At S203, the intermediate file is scanned to obtain the graphic entityinformation, thereby identifying graphic entities having an overlappingportion with the transparent area according to the profile informationof the graphic entities. A graphic entity having an overlapping portionwith the transparent area may be referred to as an overlapping graphicentity. In addition, cells of the transparent area are generated usingthe graphic entities having an overlapping portion with the transparentarea.

Consistent with the present disclosure, a cell is an area in thetransparent area in which the graphic entity properties are the same.When the graphic entities have an overlapping portion with thetransparent area and the properties of the graphic entities in theoverlapped portion are the same, the overlapping portion is taken as acell. That is, the page contents of the transparent area are dividedinto a plurality of cells, which may be of different sizes. Pixels in acell have same graphic entity properties, that is, the pixels in a cellhave same graphic entity sets. The final color value of one pixel may bea superposition result of multiple graphic entities.

Consistent with embodiments of the present disclosure, there may bethree types of cells. A first type of cell may only contain onegraph-type graphic entity or more than one graph-type graphic entities.A second type of cell may only contain one non-graph-type graphicentity, such as, for example, one image-type graphic entity or oneshading-type graphic entity. A third type of cell may contain at leasttwo types of graphic entities or contain more than one non-graph-typegraphic entity. For example, a third type of cell may contain any two orthree types of graphic entities, or contain more than one image-typegraphic entity or more than one shading-type graphic entity.

At S204, de-transparentization is performed on the graphic entities onthe first type of cells of the transparent area and the graphic entitiessubjected to de-transparentization are taken as cell graphic entities,which is, namely, the process of generating cell graphic entities, andthen the cell graphic entities are added to the intermediate file as newgraphic entities.

The de-transparentization includes transparent computing on samplingpixels, which are characteristic pixels based on the cell graphicentities.

The graphic entity properties of every pixel on the first type of cellare consistent, namely, the graphic entity sets on every pixel are thesame, so transparent computing on the graphic entities on the first typeof cell are based upon a certain characteristic pixel of the graphicentities on the entire cell, not upon every pixel on the cell. That isto say, for the first type of cell, only a certain characteristic pixelon the cell needs to be extracted for computing, and the color value ofthe characteristic pixel after computing is the color value of theentire cell without computing the pixels in the cell one by one, thussubstantially reducing the computing amount of transparent computing andimproving the assembly speed of RIP. In other words, the rasterizationspeed of RIP is improved. The color value of the graphic entities of thefirst type of cell after de-transparentization is taken as the colorvalue of the graphic entities finally drawn to the page.

The cell graphic entities resulted from transparent computing are addedto the intermediate file as new graphic entities, and correspondingly,the other graphic entities in the intermediate file are non-cell graphicentities.

At S205, the transparent area is divided into a de-transparentizing areaand an ultimate transparent area according to the type of the cellsgenerated in step S203. At this time, the whole page is divided into theultimate transparent area, the de-transparentizing area, and thenontransparent area.

Specifically, areas covered by the first type of cells and the secondtype of cells belong to the de-transparentizing area, an area covered bythe third type of cells belongs to the ultimate transparent area, andareas in the page other than the de-transparentizing area and theultimate transparent area are nontransparent areas.

At S206, the graphic entities in the ultimate transparent area, thede-transparentizing area, and the nontransparent area are respectivelyassembled.

Specifically, the graphic entities in the ultimate transparent area areassembled according to the transparent model, the graphic entities inthe de-transparentizing area are assembled according to the substitutemodel, and the graphic entities in the nontransparent area are assembledaccording to the substitute model.

Specifically, assembling the graphic entities in the de-transparentizingarea includes: if a graphic entity in the de-transparentizing area is anon-cell graphic entity and is an image-type graphic entity or ashading-type graphic entity, performing transparent computing on thesampling pixels of the graphic entity under the original coordinatespace of the graphic entity, and assembling the graphic entity subjectedto transparent computing according to the substitute model.

Assembling the graphic entities subjected to transparent computingaccording to the substitute model further comprises the following steps:if output data is in 1-bit format, the graphic entities subjected totransparent computing are zoomed from the original coordinate space toan equipment coordinate space and then screened, and the screenedgraphic entities are assembled according to the substitute model; ifoutput data is in 8-bit format, the graphic entities subjected totransparent computing are zoomed from the original coordinate space tothe equipment coordinate space, and the zoomed graphic entities areassembled according to the substitute model.

If the graphic entities in the de-transparentizing area are cell graphicentities, the cell graphic entities are directly assembled according tothe substitute model; this assembling may comprise the following steps:when outputting 1-bit data, the graphic entities are screened and thenassembled according to the substitute model; when outputting 8-bit data,the graphic entities are directly assembled according to the substitutemodel.

Wherein, the non-cell graphic entities are graphic entities obtained byinterpreting the transparent page, and the cell graphic entities are newgraphic entities generated after transparent computing; non-cellgraph-type graphic entities are skipped without any processing; andnon-cell non-transparent graphic entities are skipped as well.

The cell graphic entities are graphic entities obtained aftertransparent computing, so the color value of the cell graphic entitieshas been determined and the cell graphic entities are assembledaccording to the substitute model; for a non-cell graphic entity, eachof which is an image-type graphic entity or a shading-type graphicentity, transparent computing is performed under the original space ofthe graphic entity that has a resolution much lower than that of theequipment coordinate space, so the transparent computing amount can besubstantially reduced and the rasterization speed for a transparent pagecan be improved.

If the output is 1-bit data, the graphic entities in the ultimatetransparent area, the de-transparentizing area, and the nontransparentarea are assembled in different assembling spaces, respectively; thegraphic entities in the de-transparentizing area and the nontransparentarea are assembled in an ultimately-output 1-bit page dot matrix space,and the graphic entities in the ultimate transparent area are assembledin an 8-bit dot matrix space other than the 1-bit page dot matrix space.

If the output is 8-bit data, the graphic entities in the ultimatetransparent area, the de-transparentizing area and the nontransparentarea are assembled in the same assembling space, that is, assembled inan ultimately-output 8-bit dot matrix space.

At S207, the data assembled to the ultimate transparent area, thede-transparentizing area, and the nontransparent area is combined.

If the output is 8-bit data, the assembling spaces of all the areas inthe page are ultimately-output 8-bit dot matrix spaces, so thecombination for area data is not needed.

If the output is 1-bit data, the assembling space of the graphicentities in the ultimate transparent area is beyond theultimately-output 1-bit page dot matrix space and the assembling spacesof the graphic entities in the de-transparentizing area and thenontransparent area are within the ultimately-output 1-bit page dotmatrix space, so the assembling space in the ultimate transparent areais separated from the assembling spaces in the de-transparentizing areaand the nontransparent area. That will result in the separation of thearea data after assembling. However, the assembled area data in theultimate transparent area, the de-transparentizing area, and thenontransparent area can be combined.

Specifically, if the output is 1-bit data, the assembling space of thegraphic entities in the ultimate transparent area is the 8-bit dotmatrix space, data assembled to the ultimate transparent area isscreened as an image. The screened data uses initial tailoring of thetransparent area as current tailoring and is assembled to theultimately-output 1-bit page dot matrix space according to thesubstitute model.

At S208, all the data assembled to the page is output to the equipment.

Referring to FIG. 4, performing de-transparentization on part of thetransparent graphic entities of the transparent area and dividing thetransparent area into a de-transparentizing area and an ultimatetransparent area are all completed by a de-transparentizing unit. Thisstep may include the following steps.

At S301, the de-transparentizing unit is initialized. At this time, thenumber of cells is zero.

At S302, transparent area distribution information is imported.

The step may comprise acquiring transparent area distributioninformation, in the page resource management unit, as the transparentarea distribution information in the de-transparentizing unit.

At S303, the intermediate file is scanned to extract graphic entityinformation, including profile information of the graphic entities.Graphic entities that have an overlapping portion with the transparentarea are identified according to the profile information. Cells aregenerated by using the graphic entities having an overlapping portionwith the transparent area in the de-transparentizing unit. The so calledoverlapping portion in area means that there is an intersection in area,and the intersection mentioned below means that there is an overlappingportion in area.

Specifically, in the step of scanning the intermediate file tosequentially extract graphic entity information, the following processis performed if the profile information of the extracted graphicentities has an intersection with the transparent area in thede-transparentizing unit.

If the extracted graphic entity is a nontransparent graphic entity, theintersection of a previous cell with the graphic entity is deleted fromthe previous cell (the cell deleting operation is not performed if thereis no previous cell), the graphic entity is generated as a new cell, andthe intersection of the graphic entity with the ultimate transparentarea needs to be deleted from the ultimate transparent area.

If the extracted graphic entity is a transparent graphic entity, theintersection of a previous cell with the extracted graphic entity isdeleted from the previous cell, and the intersection is generated as anew cell. The graphic entity information on this cell is the sum of thegraphic entity information on the original cell and the information ofthis extracted graphic entity. The intersection of the extracted graphicentity with the ultimate transparent area does not generate a cell. Theremaining part of the extracted graphic entity is generated as a newcell, and the graphic entity information on this cell is the graphicentity information of the extracted graphic entity.

At S304, all of the generated cells are scanned and the cells areclassified according to the graphic entity information on the cells.

Specifically, if a cell contains transparent graphic entities and onlycontains graph-type graphic entities, the cell is of the first type; ifa cell contains transparent graphic entities and only contains oneimage-type graphic entity or one shading-type graphic entity, the cellis of the second type; and if a cell contains transparent graphicentities and contains at least two types of graphic entities or containsat least two shading-type graphic entities or two image-type graphicentities, the cell is of the third type.

At S305, de-transparentization is performed on the graphic entities onthe first type of cell, namely, transparent computing is performed onthe characteristic pixels of the graphic entities on the cell toeliminate the transparency properties.

The first type of cell is a cell only containing graphs. All the pixelson the cell has the same properties, that is, graphic entity sets onevery pixel are the same. A characteristic pixel is extracted and thetransparent computing is performed on the characteristic pixel. Theresult of this transparent computing on the characteristic pixel istaken as the final color value of the cell graphic entities. That is,the graphic entity sets on the cell are subjected to transparentcomputing to generate a cell graphic entity, and this graphic entity issubstantially a graph-type graphic entity obtained by transparentflattening. In this manner, if a cell comprises N pixels, the number oftimes that transparent computing needs to be performed is reduced by N−1times. This may be a large number in a practical application, as high as1M or even higher. The computing amount of transparent computing isreduced as compared to the conventional method where transparentcomputing is performed for all pixels one by one during assembling. Thisis because the transparent computing for graphic entities duringassembling in the conventional method is based upon the equipmentresolution. Thus, not only large computing amount of transparentcomputing is required, but also the computing formula for thetransparent computing is complex, resulting in large time cost incomputing. On the other hand, according to the present disclosure,transparent computing before assembling is based upon cells, only onetransparent computing is performed on one cell. Therefore, therasterization speed of RIP for a transparent page is improved.

At S306, the cell graphic entity, as a new graphic entity, is added tothe intermediate file in which other graphic entities are non-cellgraphic entities.

At S307, the transparent area is re-divided. Areas covered by the firsttype of cell and the second type of cell are classified into thede-transparentizing area of the de-transparentizing unit; and an areacovered by the third type of cell is classified into the ultimatetransparent area of the de-transparentizing unit.

In some embodiments, de-transparentizing may be performed on the graphicentities on the second type of cell during de-transparentizing on thegraphic entities on the first type of cell, to reduce the computingamount of transparent computing. In alternative embodiments,de-transparentizing is not performed on the graphic entities on thesecond type of cell until before the subsequent assembling, when thede-transparentizing is performed under the original coordinate space ofthe graphic entities. The reason for this is that the data amount of oneimage-type graphic entity or one shading-type graphic entity is largerthan that of a graph-type graphic entity. If image-type graphic entitiesor shading-type graphic entities on the second type of cell aresubjected to transparent computing at first, the data after computingneeds to be buffered and then read at the stage of assembling, whichincreases the required memory space and adds a reading procedure.Therefore, in the alternative embodiments, de-transparentizing is notperformed on the second type of cell when writing the intermediate file.Transparent computing is performed on image-type graphic entities orshading-type graphic entities under the original coordinate spacesthereof. Since the resolution of the original coordinate space is lowerthan that of the equipment coordinate space, the computing amount oftransparent computing on pixels under the original coordinate space isreduced as compared to the computing amount of transparent computing onimage-type graphic entities or shading-type graphic entities under theequipment coordinate space. Accordingly, the rasterization speed of RIPis improved. For example, the original space of image-type orshading-type graphic entities is typically a low-resolution space, e.g.,ranging from 72 dpi to 300 dpi. On the other hand, the equipmentresolution may be as high as 2,400 dpi or even higher. The small dataamount of transparent computing under the low-resolution space resultsin high rasterization speed of RIP.

It is noted that S305 and S306 are interchangeable in sequence, or theycan be performed simultaneously.

At S308, area distribution information is exported. Specifically, theultimate transparent area distribution information in thede-transparentizing unit is written into the ultimate transparent areadistribution information in the page resource management unit, and thede-transparentizing area distribution information in thede-transparentizing unit is written into the de-transparentizing areadistribution information in the page resource management unit. At thismoment, the page resource management unit comprises the ultimatetransparent area distribution information, the de-transparentizing areadistribution information, and the nontransparent area distributioninformation.

At S309, the de-transparentizing unit is destructed, namely all theinformation in the de-transparentizing unit is cleared.

After the above de-transparentizing is performed, graphic entities ofdifferent areas in the transparent page are assembled in differentassembling spaces.

FIG. 5 shows a process of assembling the page dot matrixes of theultimate transparent area, the de-transparentizing area, and thenontransparent area in the page resource management unit by a pageassembling unit.

As shown in FIG. 5, at S401, the page assembling unit is initialized,which may comprise initializing a nontransparent area assembling unit, ade-transparentizing area assembling unit, and an ultimate transparentarea assembling unit.

When initializing the nontransparent area assembling unit, the ultimatenontransparent area is taken as an initial tailoring of thenontransparent area assembling unit, and the ultimately-output page dotmatrix space is taken as the dot matrix assembling space for thenontransparent area regardless of 1-bit data output or 8-bit dataoutput.

When initializing the de-transparentizing area assembling unit, thede-transparentizing area is taken as an initial tailoring of thede-transparentizing are assembling unit, and the ultimately-output dotmatrix space is taken as the dot matrix assembling space for thede-transparentizing area regardless of 1-bit data output or 8-bit dataoutput.

When initializing the ultimate transparent area assembling unit, theultimate transparent area is taken as an initial tailoring of theassembling unit. If the output is 8-bit data, the ultimately-output8-bit page dot matrix space is taken as the dot matrix assembling spacefor the transparent area. If the output is 1-bit data, one 8-bit dotmatrix space is additionally created and taken as the dot matrixassembling space for the ultimate transparent area.

In some embodiments, the above initialization processes for the areaassembling units may be executed concurrently.

At S402, the intermediate file is scanned to determine whether thegraphic entity is empty. If the graphic entity is empty, the assemblingprocess is ended. Otherwise, graphic entities are acquired sequentiallyand the process proceed to S403.

In some embodiments, acquiring graphic entities sequentially is based ona sequence of the graphic entities in the intermediate file, and onlyone graphic entity may be acquired each time.

At S403, the graphic entities acquired above are delivered to thenontransparent area assembling unit for assembly.

The nontransparent area assembling unit determines whether anintersection between the profile of an acquired graphic entity and theinitial tailoring and current tailoring of the assembling unit is empty,according to the profile of the acquired graphic entity.

If the intersection is not empty and the acquired graphic entity is anontransparent graphic entity, the nontransparent area assembling unitassembles the acquired graphic entity according to the substitute model.

If the intersection is not empty and the acquired graphic entity is atransparent graphic entity, or if the intersection is empty, thenontransparent area assembling unit does not perform assembly processingon the acquired graphic entity.

After the above processing by the nontransparent area assembling unit isfinished, the acquired graphic entity is delivered to the nextassembling unit, such as the de-transparentizing area assembling unit.

At S404, the graphic entities acquired above are delivered to thede-transparentizing area assembling unit for assembly.

The de-transparentizing area assembling unit determines whether anintersection between the profile of an acquired graphic entity and theinitial tailoring and current tailoring of the assembling unit is empty,according to the profile of the acquired graphic entity.

If the intersection is not empty and the acquired graphic entity is acell graphic entity, the color value of the acquired graphic entity isdetermined and the acquired graphic entity is assembled according to thesubstitute model.

If the intersection is not empty and the acquired graphic entity is anon-cell transparent image-type or shading-type graphic entity, data ofthe acquired graphic entity is read and transparent computing isperformed under the original coordinate space of the acquired graphicentity to acquire the graphic entity data of the graphic entity afterbeing de-transparentized to perform assembly. For example, the originalcoordinate space of an image-type or a shading-type graphic entity istypically a low-resolution space, e.g., ranging from 72 dpi to 300 dpi,while the resolution of the equipment coordinate space may be as high as2,400 dpi or even higher. Therefore, performing transparent computing onpixel data under the original coordinate space may reduce the amount ofcomputing, and improve the rasterization speed of RIP.

If the acquired graphic entity is a non-cell transparent graphic entityand is neither an image-type or shading-type graphic entity, thede-transparentizing area assembling unit does not perform assemblyprocessing on the acquired graphic entity. This can avoid unnecessarydrawing and improve the rasterization speed of RIP for a transparentpage.

After the above processing by the de-transparentizing area assemblingunit is finished, the acquired graphic entity is delivered to the nextassembling unit, such as the ultimate transparent area assembling unit.

At S405, the graphic entities acquired above are delivered to theultimate transparent area assembling unit for assembly.

The specific assembly processes at S403, S404, and S405 have beenexplained above with respect to S206, and therefore the descriptionthereof is not repeated.

It is be noted that S403, S404, and S405 are interchangeable insequence, that is, for example, the acquired graphic entities can bedelivered to the ultimate transparent area assembling unit for assemblyfirst, then delivered to the nontransparent area assembling unit forassembly, and finally delivered to the de-transparentizing areaassembling unit for assembly. In addition, an acquired graphic entitymay have non-empty intersections with more than one of the three areaassembling units. Therefore, the acquired graphic entities need to bedelivered to the three assembling units for assembly, and the sequenceof delivering the graphic entities to the three assembling units is notlimited.

In some embodiments, before the assembly of the graphic entities in theentire transparent page, transparent computing may be performed onsample pixels of some of the graphic entities in thepreliminarily-divided transparent area. The sample pixels arecharacteristic pixels based on cell graphic entities or pixels based onimage-type graphic entities or shading-type graphic entities under theoriginal coordinate space. After transparent computing is performed onthe sample pixels, the obtained graphic entities are assembled in theultimately-output dot matrix space according to the substitute model,thus reducing the computing amount of transparent computing andimproving the rasterization speed of RIP.

FIGS. 6-8 schematically illustrate an exemplary process consistent withembodiments of the present disclosure.

As shown in FIG. 6, a transparent page comprises graphic entity a,graphic entity b, graphic entity c, graphic entity d, graphic entity e,graphic entity f, graphic entity g, graphic entity h, graphic entity i,graphic entity j, graphic entity k, and graphic entity I. Graphicentities a and b are nontransparent graph-type graphic entities, graphicentities c and d are transparent graph-type graphic entities, graphicentities e and f are nontransparent shading-type graphic entities,graphic entities g and h are transparent shading-type graphic entities,graphic entities i and j are nontransparent image-type graphic entities,graphic entity k is a nontransparent graph-type graphic entity, graphicentity I is a transparent image-type graphic entity. FIG. 6schematically shows profiles of the graphic entities.

Rasterization for the graphic entities in the page is performed asdescribed below.

All the graphic entities in the page are scanned. Graphic entity a,graphic entity b, graphic entity c, graphic entity d, graphic entity e,graphic entity f, graphic entity g, graphic entity h, graphic entity i,graphic entity j, graphic entity k, and graphic entity I in the page areinterpreted. The graphic entity information of the graphic entities iswritten into an intermediate file.

Particularly, graphic entity a is interpreted and the interpretedtransparency property, graphic entity type, color value, and profileinformation of graphic entity a are written into the intermediate file.

Graphic entity b is interpreted and the interpreted transparencyproperty, graphic entity type, color value, and profile information ofgraphic entity b are written into the intermediate file.

Graphic entity c is interpreted and the interpreted transparencyproperty, graphic entity type, color value, and profile information ofgraphic entity c are written into the intermediate file, and the profileinformation of graphic entity c is counted in the transparent area.

Graphic entities d, e, f, g, h, i, j, k, and I are processed. Graphicentities e, f, i, j, and k are processed in a same manner as graphicentity a, and graphic entities d, g, h, and I are processed in a samemanner as graphic entity c.

After the above processing, the graphic entity information of, e.g.,data of the graphic entities, transparency properties of the graphicentities, types of the graphic entities, color values of the graphicentities, and profiles of the graphic entities, has been written intothe intermediate file, and the profile information of transparentgraphic entities has been counted in the transparent area. Page areaother than the transparent area is the nontransparent area. Thetransparent area page distribution information and the nontransparentarea page distribution information are managed by a page resourcemanagement unit. In this case, the transparent area in the page resourcemanagement unit is schematically shown in FIG. 7.

Afterwards, de-transparentization is performed on some of the graphicentities of the transparent area in the page resource management unit,and the transparent area is divided into a de-transparentizing area andan ultimate transparent area. The de-transparentizing area distributioninformation and the ultimate transparent area distribution informationare written into the page resource distribution management unit. Thede-transparentization on some of the graphic entities of the abovetransparent area is performed by a de-transparentizing unit, asdescribed below.

The de-transparentizing unit is initialized. At this time, the number ofcells is 0.

The graphic entity distribution information of the transparent area inthe page resource management unit is imported to the de-transparentizingunit. Specifically, the de-transparentizing unit acquires thetransparent area distribution information of the graphic entities in thepage resource distribution management unit and takes the transparentarea distribution information as the transparent area distributioninformation in the de-transparentizing unit. The transparent areadescribed below is the transparent area in the de-transparentizing unit.

The intermediate file is scanned to extract graphic entity informationof graphic entity a, graphic entity b, graphic entity c, graphic entityd, graphic entity e, graphic entity f, graphic entity g, graphic entityh, graphic entity i, graphic entity j, graphic entity k, and graphicentity I to generate cell graphic entities, as described below.

The profile information of graphic entity a is acquired, and whetherthere is an intersection between an area covered by graphic entity a andthe transparent area is determined. Since graphic entity a does notintersect with the transparent area, no processing is performed ongraphic entity a.

The profile information of graphic entity b is acquired, and whetherthere is an intersection between an area covered by graphic entity b andthe transparent area is determined. Since graphic entity b does notintersect with the transparent area, no processing is performed ongraphic entity b.

The profile information of graphic entity c is acquired, and whetherthere is an intersection between an area covered by graphic entity c andthe transparent area is determined. Since graphic entity c intersectswith the transparent area, and since no previous cell exists and graphicentity c is a transparent graphic entity, a new cell Cell_0 is generatedbased on graphic entity c. The information on Cell_0 is graphic entityc.

The profile information of graphic entity d is acquired, and whetherthere is an intersection between an area covered by graphic entity d andthe transparent area is determined. Since graphic entity d intersectswith the transparent area, and since the number of previous cells is 1and graphic entity d is a transparent cell intersecting with Cell_0, theintersection of graphic entity d with Cell_0 is deleted and theremaining part is generated as Cell_1. The information on Cell_1 isgraphic entity d; The intersection of Cell_0 with graphic entity d isgenerated as Cell_2. The information on Cell_2 is a graphic entitycombination of graphic entities c and d. The remaining part of Cell_0after the intersection with graphic entity d is deleted is taken asCell_0 retention. The information on Cell_0 retention is only graphicentity c.

Graphic entities e and f are processed in a same manner as graphicentity a.

The profile information of graphic entity g is acquired, and whetherthere is an intersection between an area covered by graphic entity g andthe transparent area is determined. Since graphic entity g intersectswith the transparent area, and since the number of previous cells is 3and graphic entity g is a transparent graphic entity, graphic entity gis generated as a new cell Cell_3. The information on Cell_3 is graphicentity g.

The profile information of graphic entity h is acquired, and whetherthere is an intersection between an area covered by graphic entity h andthe transparent area is determined. Since graphic entity h intersectswith the transparent area, and since the number of previous cells is 4and graphic entity h is a transparent cell intersecting with Cell_3, theintersection of graphic entity h with Cell_3 is deleted and theremaining part is generated as Cell_4. The information on Cell_4 isgraphic entity h. The intersection of Cell_3 with graphic entity g isgenerated as Cell_5. The information on Cell_5 is a graphic entitycombination of Cell_3 and graphic entity h. The remaining part of Cell_3after the intersection with graphic entity h is deleted is taken asCell_3 retention. The information on Cell_0 retention is only graphicentity c.

Graphic entities i and j are processed in a same manner as graphicentity a.

The profile information of graphic entity k is acquired, and whetherthere is an intersection between an area covered by graphic entity k andthe transparent area is determined. Since graphic entity k intersectswith the transparent area, and since the number of previous cells is 6and graphic entity k is a nontransparent graphic entity, theintersection between graphic entity k and the transparent area is takenas a cell Cell_6. The information on Cell_6 is graphic entity k.

The profile information of graphic entity I is acquired, and whetherthere is an intersection between an area covered by graphic entity I andthe transparent area is determined. Since graphic entity I intersectswith the transparent area and the number of previous cells is 7, theintersection between graphic entity I and Cell_6 is deleted and theremaining part is generated as Cell_7. The profile of Cell_6 keepsunchanged, but the information on Cell_6 becomes a graphic entitycombination of graphic entities k and I.

In this case, the generated cells are shown in FIG. 8, including Cell_0retention, Cell_1, Cell_2, Cell_3 retention, Cell_4, Cell_5, Cell_6, andCell_7.

The above cells are scanned and classified, as follows.

The cell Cell_0 retention is acquired, on which there is a transparentgraphic entity that is only one graph-type graphic entity. Therefore,Cell_0 retention is a first type of cell.

The cell Cell_1 is acquired, on which there is a transparent graphicentity that is only one graph-type graphic entity. Therefore, Cell_1 isa first type of cell.

The cell Cell_2 is acquired, on which there are transparent graphicentities that are two graph-type graphic entities. Therefore, Cell_2 isa first type of cell.

The cell Cell_3 is acquired, on which there is a transparent graphicentity that is one shading-type graphic entity. Therefore, Cell_3 is asecond type of cell.

The cell Cell_4 is acquired, on which there is a transparent graphicentity that is one shading-type graphic entity. Therefore, Cell_4 is asecond type of cell.

The cell Cell_5 is acquired, on which there are transparent graphicentities that are two shading-type graphic entities. Therefore, Cell_5is a third type of cell.

The cell Cell_6 is acquired, on which there are transparent graphicentities that are one graph-type graphic entity and one image-typegraphic entity. Therefore, Cell_6 is a third type of cell.

The cell Cell_7 is acquired, on which there is a transparent graphicentity that is one image-type graphic entity. Therefore, Cell_7 is asecond type of cell.

Perform de-transparentizing on the graphic entities of the first type ofcells. Add the graphic entities generated after the de-transparentizingto the intermediate file as cell graphic entities, as described below.

Transparent computing is performed on the graphic entities on Cell_0retention, obtaining Cell_0 retention graphic entities. Color valuesafter the transparent computing are taken as the final color values ofthe graphic entities on Cell_0 retention, and the Cell_0 retentiongraphic entities are written into the intermediate file as new graphicentities.

Transparent computing is performed on the graphic entities on theCell_1, obtaining Cell_1 graphic entities. Color values after thetransparent computing are taken as the final color values of the graphicentities on Cell_1, and the Cell_1 graphic entities are written into theintermediate file as new graphic entities.

Transparent computing is performed on the graphic entities on Cell_2,obtaining Cell_2 graphic entities. Color values after the transparentcomputing are taken as the final color values of the graphic entities onCell_2, and Cell_2 graphic entities are written into the intermediatefile as new graphic entities.

Graphic entities on other cells may not be subjected to transparentcomputing, and thus no cell graphic entity is generated from thosegraphic entities.

The area is divided into the ultimate transparent area and thede-transparentizing area.

Cell_0 retention, Cell_1, and Cell_2 are the first type of cells.Therefore, areas covered by Cell_0 retention, Cell_1, and Cell_2 areincluded in the de-transparentizing area.

Cell_3 is the second type of cell. Since a large amount of informationis contained in the shading-type graphic entities on Cell_3,de-transparentizing computing is not performed on the graphic entitieson this cell at this stage to reduce the reading procedure for data inthe final assembly process. An area covered by Cell_3 is included in thede-transparentizing area.

Cell_4 is the second type of cell. Since a large amount of informationis contained in the shading-type graphic entities on Cell_4,de-transparentizing computing is not performed on the graphic entitieson this cell at this stage to reduce the reading procedure for data inthe final assembly process. An area covered by Cell_4 is included in thede-transparentizing area.

Cell_5 is the third type of cell. An area covered by the cell isincluded in the ultimate transparent area.

Cell_6 is the third type of cell. An area covered by the cell isincluded in the ultimate transparent area.

Cell_7 is the second type of cell. Transparent computing is notperformed on the graphic entities on this cell, and an area covered bythe cell is included in the de-transparentizing area.

In this case, the graphic entities in the intermediate file include:graphic entity a, graphic entity b, graphic entity c, graphic entity d,graphic entity e, graphic entity f, graphic entity g, graphic entity h,graphic entity i, graphic entity j, graphic entity k, graphic entity I,the Cell_0 retention graphic entity, the Cell_1 graphic entity, and theCell_2 graphic entity.

In this case, the transparent area in the de-transparentizing unit isdivided into the de-transparentizing area and the ultimate transparentarea.

The area distribution information is then exported. That is, thede-transparentizing area distribution information and the ultimatetransparent area distribution information in the de-transparentizingunit are exported to the page resource distribution management unit andserve as the de-transparentizing area distribution information and theultimate transparent area distribution information in the page resourcedistribution management unit, i.e., as the de-transparentizing area andthe ultimate transparent area in the page resource distributionmanagement unit. Data information in these areas are data information inthe next assembly.

Finally, after the above de-transparentizing process, the page resourcemanagement unit includes the de-transparentizing area, the ultimatetransparent area, and the nontransparent area. The page contents, i.e.,the graphic entities, of the three areas are respectively assembled, asdescribed below.

The page assembling unit is initialized, which may comprise initializinga nontransparent area assembling unit, a de-transparentizing areaassembling unit, and an ultimate transparent area assembling unit

When initializing the nontransparent area assembling unit, the ultimatenontransparent area is taken as an initial tailoring of thenontransparent area assembling unit. The ultimately-output page dotmatrix space is taken as the dot matrix assembling space of thenontransparent area.

When initializing the de-transparentizing area assembling unit, thede-transparentizing area is taken as an initial tailoring of thede-transparentizing assembling unit. The ultimately-output dot matrixspace is taken as the dot matrix assembling space of thede-transparentizing area.

When initializing the ultimate transparent area assembling unit, theultimate transparent area is taken as an initial tailoring of theassembling unit. If data output to the page is 8-bit data, theultimately-output page dot matrix space is taken as the dot matrixassembling space for the ultimate transparent area. If data output tothe page is 1-bit data, one 8-bit dot matrix space is additionallycreated and taken as the dot matrix assembling space for the transparentarea.

The intermediate file is scanned to acquire the graphic entities, whichare delivered to the three assembling units for assembly. The sequenceof the graphic entities in the intermediate instruction file may be a,b, c, d, e, f, g, h, i, j, k, I, Cell_0 retention, Cell_1, and Cell_2.

When assembling graphic entity a, the information of graphic entity a isacquired. Graphic entity a is a nontransparent graphic entity and has anintersection with the nontransparent area.

If data output to the page is 8-bit data, graphic entity a is directlyassembled by the nontransparent area assembling unit according to thesubstitute model.

If data output to the page is 1-bit data, graphic entity a is firstscreened as 1-bit data by the nontransparent area assembling unit. Theintersection is assembled according to the substitute model based oncurrent tailoring. Graphic entity a is not processed by thede-transparentizing area assembling unit and the ultimate transparentarea assembling unit.

Assembly for graphic entity b is the same as that for graphic entity a.

When assembling graphic entity c, the information of graphic entity c isacquired. Graphic entity c is a transparent graphic entity, has anintersection with the de-transparentizing area, and is a graph-typegraphic entity. Therefore, graphic entity c is not processed by thede-transparentizing area assembling unit. Thus, unnecessary drawing canbe avoided, and the rasterization speed of RIP for a transparent pagecan be improved.

Assembly for graphic entity d is the same as that for graphic entity c.

Assembly for graphic entities e and f are the same as that graphicentity a.

When graphic entity g is assembled, the information of graphic entity gis acquired. Graphic entity g is a transparent graphic entity and has anintersection with both the de-transparentizing area and the ultimatetransparent area. The part of graphic entity g belonging to thede-transparentizing area is subjected to transparent computing under theoriginal space of the graphic entities, and the color value of thegraphic entity after computing is taken as the final color value of theposition of the graphic entity.

If data output to the page is 8-bit data, graphic entity g is zoomed tothe equipment coordinate space by the de-transparentizing areaassembling unit, and the zoomed graphic entity is assembled directlyaccording to the substitute model.

If data output to the page is 1-bit data, graphic entity g is zoomed andthen screened by the de-transparentizing area assembling unit, and thegraphic entity is assembled directly according to the substitute model.

The part of graphic entity g belonging to the ultimate transparent areais assembled according to the transparent model and finally assembled tothe ultimately-output dot matrix space according to the substitutemodel.

Assembly for graphic entity h is the same as that for graphic entity g.

Assembly for graphic entities i and j are the same way as that forgraphic entity a.

When graphic entity k is assembled, the information of graphic entity kis acquired. Graphic entity k is a nontransparent graphic entity and hasan intersection with both the nontransparent area and the ultimatetransparent area. The part of graphic entity k belonging to thenontransparent area is assembled in the same manner as graphic entity a,the part of graphic entity k belonging to the ultimate transparent areais assembled according to the transparent model, as described below.

If data output to the page is 8-bit data, assembly is performed in theultimately-output dot matrix space.

If data output to the page is 1-bit data, assembly is performed in a8-bit dot matrix space additionally created.

Assembly for the graphic entity I is assembled the same as that forgraphic entity g.

For Cell_0 retention, since this type of graphic entity only belongs tothe de-transparentizing area, and the color value thereof is a colorvalue that has been subjected to transparent computing, it may beassembled as follows.

If data output to the page is 8-bit data, the graphic entity isassembled directly by the de-transparentizing area assembling unit underthe 8-bit page dot matrix space according to the substitute model.

If data output to the page is 1-bit data, the graphic entity is screenedas 1-bit data by the de-transparentizing area assembling unit under the1-bit page dot matrix space and assembled according to the substitutemodel.

Cell_1 and Cell_2 are assembled in the same manner as Cell_0 retention.

After the assemblies in the three areas are completed, data on the pageis divided into three parts: nontransparent area data,de-transparentizing area data, and ultimate transparent area data. Thedata of the three areas is combined and output.

FIG. 9 schematically shows an apparatus for rasterizing a transparentpage consistent with embodiments of the present disclosure. Theapparatus comprises a page description language interpreting unit 11.The page description language interpreting unit ills configured tointerpret graphic entities in a transparent page to obtain the graphicentities, transparency properties of the graphic entities, and profileinformation of the graphic entities; and to divide the transparent pageinto a transparent area and a nontransparent area according to thetransparency properties of the graphic entities.

As shown in FIG. 9, the apparatus also comprises a de-transparentizingunit 12. The de-transparentizing unit 12 is configured to determinegraphic entities having an overlapping portion with the transparent areaaccording to the profile information of the graphic entities, and todivide the transparent area into a de-transparentizing area and anultimate transparent area by using the graphic entities having anoverlapping portion with the transparent area.

The apparatus shown in FIG. 9 further comprises an assembling unit 13configured to assemble the graphic entities in the de-transparentizingarea, the graphic entities in the ultimate transparent area, and thegraphic entities in the nontransparent area.

FIG. 10 shows an example of the assembling unit 13. As shown in FIG. 10,the assembling unit 13 comprises a de-transparentizing area assemblingunit 131 configured to assemble the graphic entities in thede-transparentizing area, a nontransparent area assembling unit 132configured to assemble the graphic entities in the nontransparent area,and an ultimate transparent area assembling unit 133 configured toassemble the graphic entities in the ultimate transparent area.

The de-transparentizing unit 12 is also configured to generate cells byusing the graphic entities having an overlapping portion with thetransparent area, and to divide the transparent area into ade-transparentizing area and an ultimate transparent area according tothe types of the cells. A cell is an area having the same graphic entityproperties in the transparent area. When the graphic entities have anoverlapping portion with the transparent area and the properties of thegraphic entities on the overlapping portion are the same, theoverlapping portion is taken as the a cell.

The de-transparentizing unit 12 is further configured to divide thetransparent area into a de-transparentizing area and an ultimatetransparent area according to the type of the cell. An area covered bythe cell is written into the de-transparentizing area if the cell is afirst type of cell. An area covered by the cell is written into thede-transparentizing area if the cell is a second type of cell. An areacovered by the cell is written into the ultimate transparent area if thecell is a third type of cell. The first type of cell is a cell onlycontaining image-type graphic entities. The second type of cell is acell only containing one image-type graphic entity or one shading-typegraphic entity. The third type of cell is a cell at least containing twotypes of graphic entities or at least containing two image-type graphicentities or two shading-type graphic entities.

The de-transparentizing unit 12 is further configured to, if thegenerated cells are the first type of cells, perform transparentcomputing on the graphic entities in the cells before an area covered bythe first type of cells is written into the de-transparentizing area, soas to obtain cell graphic entities.

The assembling unit 13 is specifically configured to assemble thegraphic entities in the de-transparentizing area according to thesubstitute model, to assemble the graphic entities in the ultimatetransparent area according to the transparent model, and to assemble thegraphic entities in the nontransparent area according to the substitutemodel.

Assembling the graphic entities in the de-transparentizing areaaccording to the substitute model by the assembling unit 13 comprises:

If a graphic entity in the de-transparentizing area is one image-typegraphic entity or one shading-type graphic entity, performingtransparent computing on the graphic entity in the original coordinatespace of the graphic entity, and assembling the graphic entity subjectedto the transparent computing according to the substitute model.

If the graphic entities in the de-transparentizing area are cell graphicentities, assembling the cell graphic entities according to thesubstitute model.

Assembling the graphic entities subjected to transparent computingaccording to the substitute model by the assembling unit 13 furthercomprises:

If the output is 1-bit data, zooming the graphic entities from theoriginal coordinate space to the equipment coordinate space andscreening the zoomed graphic entities, and assembling the screenedgraphic entities according to the substitute model.

If the output is 8-bit data, zooming the graphic entities from theoriginal coordinate space to the equipment coordinate space, andassembling the zoomed graphic entities according to the substitutemodel.

The assembling unit 13 is further configured to assemble, if the outputis 1-bit data, the graphic entities in the ultimate transparent area,the de-transparentizing area, and the nontransparent area in differentdot matrix spaces respectively; and to assemble, if the output is 8-bitdata, the graphic entities in the ultimate transparent area, thede-transparentizing area, and the nontransparent area in the same dotmatrix space.

The assembling unit 13 is further configured to assemble, if the outputis 1-bit data, the graphic entities in the de-transparentizing area andthe nontransparent area in an ultimately-output 1-bit page dot matrixspace, and the graphic entities in the ultimate transparent area in an8-bit dot matrix space; and to assemble, if 8-bit data is output, thegraphic entities in the ultimate transparent area, thede-transparentizing area, and the nontransparent area in anultimately-output 8-bit page dot matrix space.

FIG. 11 schematically shows another exemplary apparatus for rasterizinga transparent page consistent with embodiments of the presentdisclosure. As compared to the apparatus shown in FIG. 9, the apparatusshown in FIG. 11 further comprises an area data combining unit 14.

The area data combining unit 14 is configured to, if 1-bit output datais output, combine all the assembled data and output the combined datato equipment after the graphic entities in the ultimate transparentarea, the de-transparentizing area, and the nontransparent area areassembled.

Combining all the assembled data and outputting the combined data toequipment by the area data combining unit 14 specifically comprises:screening the graphic entities in the ultimate transparent area asimages, assembling the graphic entities to an ultimately-output 1-bitpage dot matrix space according to the substitute model, and outputtingall the data assembled to the 1-bit page dot matrix space to theequipment.

Consistent with embodiments of the present disclosure, a page ispreliminarily divided into a transparent area and a nontransparent areaaccording to the transparency properties of graphic entities aftergraphic entity information is generated by interpreting the page. Cellsare generated from the graphic entities in the transparent area. Thegraphic entities on the cells are subjected to de-transparentizingaccording to the types of the cells. The transparent area is dividedinto a de-transparentizing area and an ultimate transparent area. Thegraphic entities in the three areas are assembled according to differentassembly models, i.e., the graphic entities in the nontransparent areaand in the de-transparentizing area are assembled according to thesubstitute model, and the graphic entities in the ultimate transparentarea are assembled according to the transparent model. Transparentcomputing is performed on sample pixels of the transparent graphicentities before graphic entity assembly, and the process of thistransparent computing is based upon pixels of cell graphic entities orupon pixels of image-type or shading-type graphic entities under theoriginal coordinate space thereof, which is different from thetransparent computing in the conventional method that is performed underthe equipment coordinate space. The resolution of the originalcoordinate space may be lower than that of the equipment coordinatespace. Therefore, the computing amount of transparent computing on thegraphic entities under the original coordinate space is reduced and therasterization speed of RIP for a transparent page is improved.

It shall be understood by those skilled in the prior art that, theembodiments of the present disclosure may be provided as methods,systems or computer program products. Thus, the present disclosure maybe in the form of total hardware embodiments, total softwareembodiments, or software and hardware combined embodiments. Furthermore,the present disclosure may be in the form of computer program productsimplemented on one or a plurality of computer-readable memory media(including but not limited to disc memory unit and optical memory unit,etc.) containing computer-readable program codes therein.

The present disclosure is described with reference to the flowchartsand/or block diagrams of the methods, equipment (systems) and computerprogram products in accordance with the embodiments of the presentdisclosure. It shall be understood that each flow and/or block in theflowcharts and/or block diagrams, as well as the combination of flowsand/or blocks in the flowcharts and/or block diagrams may be implementedby computer program instructions. These computer program instructionsmay be offered to a universal computer, a dedicated computer, anembedded-type processor or the processing units of other programmabledata processing equipment to generate a machine unit, thus a device forimplementing the functions designated in one or a plurality of flows inthe flowcharts and/or one or a plurality of blocks in the block diagramsis generated via instructions executed by computers or processing unitsof other programmable data processing equipment.

These computer program instructions may also be stored in a computerreadable memory unit capable of enabling computers or other programmabledata processing equipment to operate in a specific way, thus themanufactured products including an instruction device are generated bythe instructions stored in the computer readable memory unit, and theinstruction device implements the functions designated in one or aplurality of flows in the flowcharts and/or one or a plurality of blocksin the block diagrams.

These computer program instructions may also be loaded on computers orother programmable data processing equipment, thus a series of operationsteps are executed on the computers or other programmable equipment togenerate computer-implementable processing, so that the instructionsexecuted on the computers or other programmable equipment provide thesteps of implementing the functions designated in one or a plurality offlows in the flowcharts and/or one or a plurality of blocks in the blockdiagrams.

Other embodiments of the disclosure will be apparent to those skilled inthe art from consideration of the specification and practice of theinvention disclosed herein. It is intended that the specification andexamples be considered as exemplary only, with a true scope and spiritof the invention being indicated by the following claims.

What is claimed is:
 1. A method for rasterizing a transparent page,comprising: interpreting the transparent page to obtain graphicentities, transparency properties of the graphic entities, and profileinformation of the graphic entities; dividing the transparent page intoa transparent area and a nontransparent area according to thetransparency properties of the graphic entities; identifying, from thegraphic entities, an overlapping graphic entity having an overlappingportion with the transparent area according to the profile informationof the graphic entities; and dividing the transparent area into ade-transparentizing area and an ultimate transparent area by using theoverlapping graphic entity, wherein dividing the transparent area into ade-transparentizing area and an ultimate transparent area comprises:generating a cell of the transparent area by using the overlappinggraphic entity, the cell having a same graphic entity property; dividingthe transparent area into the de-transparentizing area and the ultimatetransparent area according to a type of the cell; writing an areacovered by the cell into the de-transparentizing area if the cell is afirst type of cell or a second type of cell; and writing an area coveredby the cell into the ultimate transparent area if the cell is a thirdtype of cell, wherein: the first type of cell is a cell only containinggraph-type graphic entities; the second type of cell is a cell onlycontaining one image-type graphic entity or one shading-type graphicentity; the third type of cell is a cell at least containing two typesof graphic entities or at least containing two image-type graphicentities or two shading-type graphic entities.
 2. The method accordingto claim 1, further comprising: assembling the graphic entity in thede-transparentizing area, the graphic entity in the ultimate transparentarea, and the graphic entity in the nontransparent area.
 3. The methodaccording to claim 2, wherein assembling the graphic entity in thede-transparentizing area, the graphic entity in the ultimate transparentarea, and the graphic entity in the nontransparent area comprises:assembling the graphic entity in the de-transparentizing area accordingto a substitute model; assembling the graphic entity in the ultimatetransparent area according to a transparent model; and assembling thegraphic entity in the nontransparent area according to the substitutemodel.
 4. The method according to claim 2, wherein assembling thegraphic entity in the de-transparentizing area, the graphic entity inthe ultimate transparent area, and the graphic entity in thenontransparent area further comprises: if output data is in 1-bitformat, assembling the graphic entity in the ultimate transparent area,the graphic entity in the de-transparentizing area, and the graphicentity in the nontransparent area in different dot matrix spaces,respectively; and if output data is in 8-bit format, assembling thegraphic entity in the ultimate transparent area, the graphic entity inthe de-transparentizing area, and the graphic entity in thenontransparent area are assembled in a same dot matrix space.
 5. Themethod according to claim 2, wherein assembling the graphic entity inthe de-transparentizing area, the graphic entity in the ultimatetransparent area, and the graphic entity in the nontransparent areafurther comprises: if output data is in 1-bit format, assembling thegraphic entity in the de-transparentizing area and the graphic entity inthe nontransparent area in an ultimately-output 1-bit page dot matrixspace, and assembling the graphic entity in the ultimate transparentarea in an 8-bit dot matrix space; and if output data is in 8-bitformat, assembling the graphic entity in the ultimate transparent area,the graphic entity in the de-transparentizing area, and the graphicentity in the nontransparent area in an ultimately-output 8-bit page dotmatrix space.
 6. The method according to claim 2, further comprising:combining assembled data and outputting the combined data.
 7. The methodaccording to claim 6, wherein combining the assembled data andoutputting the combined data comprises: screening data in the ultimatetransparent area as images; assembling the data to an ultimately-output1-bit page dot matrix space according to a substitute model; andoutputting the data assembled to the 1-bit page dot matrix space.
 8. Themethod according to claim 1, further comprising: performing transparentcomputing on the graphic entities in the cell, if the cell is the firsttype of cell, before the area covered by the cell is written into thede-transparentizing area, to obtain a cell graphic entity.
 9. The methodaccording to claim 8, further comprising: assembling the graphic entityin the de-transparentizing area, the graphic entity in the ultimatetransparent area, and the graphic entity in the nontransparent area. 10.The method according to claim 9, wherein assembling the graphic entityin the de-transparentizing area comprises: if the graphic entity in thede-transparentizing area is an image-type graphic entity or anshading-type graphic entity, performing transparent computing on thegraphic entity in an original coordinate space of the graphic entity;and assembling the graphic entity subjected to transparent computingaccording to a substitute model; if the graphic entities in thede-transparentizing area is a cell graphic entity, assembling the cellgraphic entity according to the substitute model.
 11. The methodaccording to claim 10, wherein assembling the graphic entity subjectedto transparent computing according to the substitute model comprises: if1-bit data is output, zooming the graphic entity from the originalcoordinate space to an equipment coordinate space and screening thegraphic entity; and assembling the screened graphic entity according tothe substitute model; if 8-bit data is output, zooming the graphicentity from the original coordinate space to the equipment coordinatespace; and assembling the zoomed graphic entity according to thesubstitute model.
 12. A device for rasterizing a transparent page,comprising: a page description language interpreting unit configured to:interpret the transparent page to obtain graphic entities, transparencyproperties of the graphic entities, and profile information of thegraphic entities; and divide the transparent page into a transparentarea and a nontransparent area according to the transparency propertiesof the graphic entities; and a de-transparentizing unit configured to:identify, from the graphic entities, an overlapping graphic entityhaving an overlapping portion with the transparent area according to theprofile information of the graphic entities; and divide the transparentarea into a de-transparentizing area and an ultimate transparent area byusing the graphic entities respectively having an overlapping portionwith the transparent area, wherein the de-transparentizing unit isfurther configured to: generate a cell of the transparent area by usingthe overlapping graphic entity, the cell having a same graphic entityproperty; divide the transparent area into the de-transparentizing areaand the ultimate transparent area according to a type of the cell; writean area covered by the cell into the de-transparentizing area if thecell is a first type of cell or a second type of cell; and write an areacovered by the cell into the ultimate transparent area if the cell is athird type of cell, wherein: the first type of cell is a cell onlycontaining graph-type graphic entities: the second type of cell is acell only containing one image-type graphic entity or one shading-typegraphic entity; the third type of cell is a cell at least containing twotypes of graphic entities or at least containing two image-type graphicentities or two shading-type graphic entities.
 13. The device accordingto claim 12, further comprising: an assembling unit configured toassemble the graphic entity in the de-transparentizing area, the graphicentity in the ultimate transparent area, and the graphic entity in thenontransparent area.
 14. The device according to claim 13, wherein theassembling unit is further configured to: assemble the graphic entity inthe de-transparentizing area according to a substitute model; assemblethe graphic entity in the ultimate transparent area according to atransparent model; and assemble the graphic entity in the nontransparentarea according to the substitute model.
 15. The device according toclaim 13, further comprising: an area data combining unit configured tocombine assembled data and output the combined data.
 16. The deviceaccording to claim 15, wherein the area data combining unit is furtherconfigured to: screen data in the ultimate transparent area as images;assemble the data to an ultimately-output 1-bit page dot matrix spaceaccording to a substitute model; output the data assembled to the 1-bitpage dot matrix space.
 17. A non-transitory computer-readable storagemedium with an executable program stored thereon, wherein the program,when executed by at least one processor, causes a computing device toperform operations comprising: interpreting the transparent page toobtain graphic entities, transparency properties of the graphicentities, and profile information of the graphic entities; dividing thetransparent page into a transparent area and a nontransparent areaaccording to the transparency properties of the graphic entities;identifying, from the graphic entities, an overlapping graphic entityhaving an overlapping portion with the transparent area according to theprofile information of the graphic entities; and dividing thetransparent area into a de-transparentizing area and an ultimatetransparent area by using the overlapping graphic entity, whereindividing the transparent area into a de-transparentizing area and anultimate transparent area comprises: generating a cell of thetransparent area by using the overlapping graphic entity, the cellhaving a same graphic entity property; dividing the transparent areainto the de-transparentizing area and the ultimate transparent areaaccording to a type of the cell; writing an area covered by the cellinto the de-transparentizing area if the cell is a first type of cell ora second type of cell; and writing an area covered by the cell into theultimate transparent area if the cell is a third type of cell, wherein:the first type of cell is a cell only containing graph-type graphicentities; the second type of cell is a cell only containing oneimage-type graphic entity or one shading-type graphic entity; the thirdtype of cell is a cell at least containing two types of graphic entitiesor at least containing two image-type graphic entities or twoshading-type graphic entities.